Which statement about hydrostatic pressure is true?

• A. It depends on heart rate
• B. It is determined by the weight of the fluid above where measured
• C. It depends on viscosity
• D. It is independent of height

Answer: (B)

Hydrostatic pressure arises from the weight of the fluid above the measurement point. In a static column, every layer of fluid adds weight that is transmitted downward, so pressure increases with depth. Mathematically, P = ρ g h, where ρ is fluid density, g is gravity, and h is the vertical height of fluid above the point. This means the deeper you measure, the higher the pressure.

Heart rate doesn’t determine static hydrostatic pressure, since it’s a property of the fluid column at rest, not a dynamic cardiovascular metric. Viscosity affects how easily layers move and how flow occurs, but it doesn’t set the static pressure in a fluid at rest. And hydrostatic pressure clearly depends on height; saying it’s independent of height contradicts the basic relationship.